Wireless communication devices and supporting cellular networks continue to evolve at a rapid pace to support additional functionality, including a wide array of data services and faster data rates. Among the data services supported over some modern cellular networks, such as Long Term Evolution (LTE) networks, is the servicing of voice calls via a packet switched domain. For example, some LTE networks provide a service known as voice over LTE (VoLTE), in which voice calls can be serviced as packet switched calls via a voice over Internet Protocol (VoIP) connection.
However, LTE coverage is not yet universal and, as such, LTE networks are being co-deployed in overlapping regions with legacy cellular networks that support voice calls via a circuit switched domain. In this regard, wireless communication devices may transition between cellular radio access technologies (RATs) as a result of moving in and out of LTE coverage due to device mobility.
For a wireless communication device with an active voice call, transitioning between a network, such as an LTE network, that services voice calls as packet switched data sessions and a legacy network servicing voice calls as circuit switched calls can be somewhat complex. Some network operators support technology, such as single radio voice call continuity (SRVCC), to enable transitioning an active voice call between an LTE network and a legacy network. However, some network operators do not support SRVCC or other call transition mechanism, opting instead to attempt to provide universal LTE coverage for voice calls. Unfortunately, at least early in the stages of deployment of modern networks, the aspiration of providing universal LTE coverage is unlikely to be met. As such, a device moving outside of the footprint of LTE coverage during a voice call, will experience a call drop in networks that do not support SRVCC or other mechanism to transition an active voice call to a legacy network. This experience can be frustrating for users, who will have to manually reestablish the voice call following such call drops.